How About the Plasticity of Wool?
Jul. 01, 2019
Wool is often subjected to various external forces such as stretching, curling, and twisting during processing to change the original shape of the fiber. Wool Felts Because wool has good elasticity, it tries to return to its original shape, so various stresses are generated inside the fiber. This internal stress needs to be gradually attenuated until it is eliminated for a long time. It often processes wool products. Difficulties are one of the factors that make wool products less stable in size and shape during processing and use. The plasticity of wool refers to the property that the wool can be rapidly attenuated under hot and humid conditions, and the existing form can be changed according to external force, and then the shape can be maintained by cooling or drying.
The plasticity of wool is closely related to the change of its multi-chain chain conformation and the disassembly and reconstruction of the secondary bonds between the skin chains. The wool fibers subjected to tensile stress are treated in hot water or steam for a short time. Then the external force is removed and allowed to shrink in the steam, and the fiber can be shrunk to a shorter length than the original length. This phenomenon is called "over-shrinking". The reason for this phenomenon is that external forces and wet and hot effects change the conformation of the skin chain, and the original secondary key is broken. However, due to the short processing time, new sub-keys have not been established in the new position. The multi-skin chain can shrink freely, so it is over-contracted.